Many industries require controlled environments that are free from contaminants, such as in surgical suites in hospitals, pharmaceutical and biotechnology manufacturing facilities and laboratories, medical device manufacturing facilities, and micro-electronics manufacturing facilities. Such industries utilize cleanrooms to provide environments in which dust, small particles and other contaminants are reduced. Cleanrooms can function effectively only when every effort is taken to maintain the level of control necessary to preclude contamination in their controlled environments. Contamination most often is caused by workers in the cleanroom and/or by items brought into the cleanroom. The problems associated with keeping these rooms clean have not been easily solved.
Rigorous regulatory guidelines have been established, and continue to be developed, utilizing a variety of inter-related methodologies for operating cleanrooms in a manner best suited to exclude unwanted contaminants from the controlled environment. In adhering to these regulatory guidelines and assuring an acceptable environment in which to manufacture certain products, industries must be able to address known contamination with a documented control, which requires a cleaning regime that has been proven effective. Maintaining a cleaning system that is meaningful, manageable and defendable, however, becomes complex in production areas based on a multitude of variables.
One such variable that determines the effectiveness of a cleaning system is the ability to properly contact contaminants in a manner sufficient to neutralize or remove them. More specifically, a chemical agent capable of destroying the cells of contaminants needs to saturate and penetrate the cell walls over a specified contact time. Chemical agents are applied using various techniques, including using a sprayer, a mop, and/or a fogger. Although sprayers, mops with buckets and foggers have all been utilized in varying capacities and with varying success in cleanroom applications, the more of these separate components that are introduced into the controlled environment of a cleanroom, the greater the likelihood of introducing contaminants into the controlled environment.
Even when few components are introduced into a cleanroom, the likelihood of introducing contaminants along with the components increases every time a component must be removed and re-introduced into the controlled environment during the cleaning operation. For example, the use of a mop with a bucket results in “dirty water” mopping, which may actually contribute to the spread of contaminants. The bucket, therefore, must be routinely emptied and refilled. This not only increases the likelihood of introducing contaminants into the cleanroom, it also increases the volume of cleaning agents required to complete the cleaning operation.
In an attempt to address the above issues, at least one system has been developed that includes a sprayer, a sponge mop and a fogger all in one unit. This prior art system, illustrated in FIGS. 1 and 2, is offered by Veltek Associates, Inc. under the name CORE2CLEAN. The unit includes a re-sealable pressure vessel 2 for storing cleaning solutions, such as disinfectant, therein so as to protect the cleaning solution from contaminants when the unit is being used in a cleaning operation. The vessel 2 can be un-sealed by removing a vessel lid 4, at which point a cleaning solution may be placed in or removed from the vessel 2. The vessel 2 is autoclavable inside and out in the un-sealed configuration. After cleaning solution is placed in the vessel 2, it can be sealed from external contaminants by installing the vessel lid 4.
Cleaning solution can be dispensed from the sealed vessel 2 via the sprayer, sponge mop or fogger on an as-needed basis, thereby eliminating contamination due to the need to change dirty cleaning solutions during cleanroom washing, which also reduces the total volume of cleaning solution required to perform a cleaning operation. To provide the ability to dispense a continuous flow of cleaning solution in this unit, however, the system is operated by compressed gas, such as compressed air. The use of compressed air in a pressure vessel 2 creates many potential dangers arising from a potential sudden release of the pressure. Accordingly, safe operation of such a system requires implementation of various pressure regulating devices.
As illustrated in FIG. 1, the prior art system includes a pressure vessel 2 having a vessel lid 4, a handle 6, a first connection point 8, and a second connection point 10. The vessel lid 4 can be removed to access the inside of the vessel 2 to add or remove contents, such as cleaning solutions. The vessel lid 4 maintains an airtight seal in the vessel 2 when installed. The handle 6 is used to facilitate removal and installation of the vessel lid 4.
As illustrated in FIG. 2, the prior art system also includes a drain valve 12, an outlet regulator assembly 14, and an inlet regulator assembly 26. The drain valve 12 is located substantially at the bottom of the vessel 2 and is used to drain cleaning and rinsing solutions out of the vessel 2 when the vessel 2 is being cleaned. The outlet regulator assembly 14 is installed at the first connection point 8 and is used to dispense cleaning solution from the vessel using a cleaning applicator, such as a sprayer, sponge mop or fogger. The inlet regulator assembly 26 is installed at the second connection point 10 and is used to charge the vessel 2 with air pressure. The outlet regulator assembly 14 and the inlet regulator assembly 26 are removable from the vessel 2 so the vessel 2 may be properly autoclaved.
The first connection point 8 includes a dip tube assembly 16 that is in fluid communication with the bottom of the vessel 2 so that cleaning solution can be extracted therefrom. Because only the first connection point 8 includes a dip tube assembly 16 for extracting fluids from the bottom of the vessel 2, the outlet regulator assembly 14 and the inlet regulator assembly 26 cannot be interchangeably installed on the first connection point 8 and the second connection point 10. Accordingly, the outlet regulator assembly 14 can only be installed at the first connection point 8. Further, both the first connection point 8 and the second connection point 10 include internal check-type valves that are in the closed position to prevent fluid communication between the inside of the vessel 2 and the outside of the vessel 2 when the outlet regulator assembly 14 and the inlet regulator assembly 26 are not respectively installed therein.
As used herein, the term “fluid communication” includes a path by which liquids or gases may move between two or more structures. The term “gas communication” includes a path by which gases, such as air or steam, may move between two or more structures. Also herein, the terms “air” and “gas” are used interchangeably, unless otherwise apparent from the context.
The outlet regulator assembly 14 of the prior art system includes an outlet connector 18, an inlet connector 20, an outlet manual control valve 22, and an outlet pressure gauge 24. When using the system to dispense cleaning solution, cleaning applicators, such as a sprayer, sponge mop and fogger, are interchangeably connected to the outlet regulator assembly 14 at the outlet connector 18. With the cleaning applicator connected to the outlet regulator assembly 14, the outlet regulator assembly 14 is then installed on the vessel 2 at the first connection point 8 via the inlet connector 20 of the outlet regulator assembly 14. After the vessel 2 has been charged, a user may manually adjust the pressure with which the cleaning solution is dispensed from the vessel 2 by opening or closing the outlet manual control valve 22 as required until the desired pressure is observed on the outlet pressure gauge 24. Charging the vessel 2 is described in more detail below with reference to the inlet regulator assembly 26.
The inlet regulator assembly 26 of the prior art system includes an outlet connector 28, an inlet connector 30, an inlet manual control valve 32, a relief valve 34, an inlet pressure gauge 36, and a manual purge valve 38. To place a charge on the vessel 2, the inlet regulator assembly 26 is installed on the vessel 2 at the second connection point 10 via the outlet connector 28 of the inlet regulator assembly 26. With the inlet regulator assembly 26 installed on the vessel 2, a charging device (not shown), such as a pressurized tank or line, is then installed at the inlet connector 30 of the inlet regulator assembly 26. The user must then open the inlet manual control valve 32 to allow air pressure in the charging device to be transferred into the vessel 2. The user must manually adjust the air pressure in the vessel 2 by opening or closing the inlet manual control valve 32 as required until the desired pressure is observed on the inlet pressure gauge 36.
If the pressure inside the vessel 2 reaches a predetermined value, such as 100 psi, or greater at any point while the inlet regulator assembly 26 is installed on the vessel 2, the relief valve 34 will release some of the air pressure to prevent the air pressure within the vessel 2 from exceeding the predetermined value. Excess pressure can be released from the vessel 2 in this manner, however, only when the inlet regulator assembly 26 is installed on the vessel 2. There are no means by which to relieve excess pressure from the vessel 2 when the inlet regulator assembly 26 is not installed on the vessel 2.
The inlet regulator assembly 26 of the prior art system is also used to purge the vessel 2 of air to remove any pressure within the vessel 2. The vessel 2 may need to be purged, for example, before checking or servicing any part of the system, before loosening or removing the vessel lid 4, or after the user has concluded use of the system. To purge the system, the inlet regulator assembly 26 must be installed on the vessel 2 at the second connection point 10 via the outlet connector 28 of the inlet regulator assembly 26. There is fluid communication between the manual purge valve 38 and the vessel 2 whenever the inlet regulator assembly 26 is installed on the vessel 2 at the second connection point 10. Accordingly, the prior art system may be purged using inlet manual control valve 32, the manual purge valve 38, or a combination thereof, but the inlet regulator assembly 26 must be installed on the vessel 2 at the second connection point 10.
To purge the prior art system while the charging device is installed at the inlet connector 30 of the inlet regulator assembly 26, the inlet manual control valve 32 must be in the closed position so that air from the charging device is not continuously supplied to the vessel 2, thereby preventing proper purging. The inlet manual control valve 32 includes an orifice that is in fluid communication with the outside of the vessel 2 when the inlet manual control valve 32 is closed. Accordingly, air may escape from the vessel 2 via the orifice when the inlet manual control valve 32 is closed, thereby purging the vessel 2. The vessel 2 is therefore purged by closing the inlet manual control valve 32 if the charging device is installed in the inlet regulator assembly 26. The manual purge valve 38 may also be opened in this configuration to allow air within the vessel to escape therethrough, the manual purge valve 38 thereby operating simultaneously with the orifice of the inlet manual control valve 32 to purge the vessel.
The prior art system, however, is more likely to be purged with the charging device removed from the inlet connector 30 of the inlet regulator assembly 26. To purge the vessel 2 with the charging device removed from the inlet regulator assembly 26, the inlet manual control valve 32 may be in the open or closed position. The vessel 2 may be purged by placing the inlet manual control valve 32 in the closed position, thereby allowing air within the vessel 2 to escape through the orifice in the inlet manual control valve 32. The manual purge valve 38 may also be opened in this configuration to allow air within the vessel to escape therethrough, the manual purge valve 38 thereby operating simultaneously with the orifice of the inlet manual control valve 32 to purge the vessel. The vessel may also be purged by placing the inlet manual control valve 32 in the open position. With the inlet manual control valve 32 in the open position, air within the vessel 2 may not escape through the orifice in the inlet manual control valve 32. Accordingly, the manual purge valve 38 is opened to allow air to escape from the vessel 2 when the inlet manual control valve 32 is in the open position, thereby purging the vessel 2.
Thus, a manual purge valve 38 and inlet pressure gauge 36 must be disposed on the inlet regulator assembly 26 to purge the system. Accordingly, the inlet regulator assembly 26 must be installed on the vessel 2 of the prior art system to purge that system. This is not only an unnecessarily complicated configuration, it also poses certain safety risks.
Using the inlet manual control valve 32, the manual purge valve 38, or a combination thereof as described above, the subject valve(s) remain open until the user observes a pressure of zero (0) psi on the inlet pressure gauge 36 and can no longer hear air escaping the vessel 2. After the vessel 2 is purged, the inlet regulator assembly 26 is removed from the vessel 2 to allow the vessel 2 to be sterilized by a process such as autoclaving. Autoclaving includes utilizing high temperature steam in a sterilization process.
To autoclave the vessel, the vessel lid 4 must be removed and the drain valve 12 is opened to allow steam to pass through the vessel 2. The outlet regulator assembly 14 and the inlet regulator assembly 26 are removed from the vessel 2 during autoclaving because they are not autoclavable. The outlet regulator assembly 14 and the inlet regulator assembly 26 are not autoclavable because they are not configured to allow steam to pass therethrough and because their respective components 18-24 and 28-38 are not designed to withstand the high temperatures associated with autoclaving. Thus, the outlet connector 18, inlet connector 20, outlet manual control valve 22, and outlet pressure gauge 24 of the outlet regulator assembly 14 and the outlet connector 28, inlet connector 30, inlet manual control valve 32, relief valve 34, inlet pressure gauge 36, and manual purge valve 38 of the inlet regulator assembly 26 are all not autoclavable. These components, therefore, can trap bacteria therein, which will adversely affect a subsequent cleaning operation using the system, thereby reducing the reliability and control of the system. Accordingly, there is a present need for a system for effectively washing cleanrooms in which all of the components are autoclavable, and in which the steps of charging, operating, and purging the system are both simpler and safer.